Method for producing an open mesh fabric of glass fibers



Dec. 29, 1953 e. SLAYTER I 2,664,375

METHOD FOR PRODUCING AN OPEN MESH FABRIC 0F GLASS FIBERS Original FiledMarch 6, 1947 2 Sheets-Sheet l HIIllllllrlllfilllllllllflllllll INVENTORGames J/ayfer Dec. 29, 1953 G. SLAYTER 2,664,375

METHOD FOR PRODUCING AN OPEN MESH FABRIC OF GLASS FIBERS Original FiledMarch a, 1947 2 Sheets-Sheet 2 III E: 4.

- INVENTOR Games J/ayfer Patented Dec. 29, 1953 METHOD FOR PRODUCING ANOPEN .MESH FABRIC OF GLASS FIBERS Games Slayter, Newark, Ohio, assignorto Owens- Corning Fibergias Corporation, a corporation or DelawareOriginal application March 6,

1947, Serial N 0.

732,671. Divided and this application June 9, 1949, Serial No. 98,002

2 Claims.

This invention relates to a process and apparatus for producing fabrics.or mats of glass fibers. One of the principal objects of the inventionis to speedily and efiiciently fabricate a relatively thin mat of glassfibers having the characteristics of high strength in directions in theplanes of its major surfaces, porosity and formability whereby it iswell adapted for application as a resinous reinforcement in molded andlaminated plastics and as a reinforcing filler in shingles, separators,pipe wrap, or as an interlayer with other fabrics of lower strength, andas a base fabric to be coated in making coated cloth.

Another object of this invention is to produce by simple and inexpensivemeans a fabric of glass fibers having exceptionally high strengths as aresult of the arrangement of the fibers predominantly as bundles ofselected concentrations, which are disposed at predetermined anglesrelative to each other.

A further object is to produce a fabric of glass fibers which may bestretched in directions in the planes of its major surfaces to effect arearrangement of the angular relationship between fibers that willincrease the dimensions while decreasing the thickness or fiberconcentrations of the fabric and at the same time improving its massintegrity without noticeable impairment of its strength, porosityor'formability.

These and other objects of this invention will hereinafter appear andfor purposes of illustration but not of limitation, embodiments of theinvention are shown'in the accompanying drawings, in which:

Figure 1 is a diagrammatic illustration of a means for manufacturing afabric of glass fibers in cooperation with the fiber forming device;

Figure 1A is a schematic illustration of afabric forming processemploying multiple strands simultaneously as provided by one or morefiber forming devices;

Figure 2 is an enlarged perspective view of a portion of the matproduced by the process illustrated in Figure 1;

Figure 3 is a diagrammatic illustration of another unit operation forproducing a mat of glass fibers in cooperation with the fiber formingdevice;

Figure 4 is a schematic illustration of the process for stretching themat produced by the processes illustrated in Figures 1, 1A and 3 and atthe same time combining another fabric therewith;

Figure 5 is an enlarged perspective view of a portion of the matproduced by the apparatus in Figures 1, 1A or 3 but after it has been.stretched in, one ormore directions; and

,pairment of the layersare formed on the drum with the strands in onelayer being disposed generally in the same direction but angular-1y withrespect to the strands in the adjacent layers. The number of layers aswell as the angular relationship of the strands between layers may beselected to impart the characteristics desired in the fabric, such, forexample, as wall thickness, porosity, and directional strength. Thefabric, when removed from the drum, may be further processed as bystretching in directions parallel with its major faces to effectrelative angular movement between strands in the same layer and betweenstrands in adjacent layers which results in thinning the fabriccommensurate with the increase in the dimensions of the fabric. In thestretching, some intertangling of fibers may take place to improve themass integrity of the final product.

The product of this invention consists first of a fabric of glass fibersparallelly arranged in the form of bundles, the bundles being disposedin multiple layers with the bundles in each layer extending generally inthe same direction but at a selected angular relationship with thebundles in the adjacent layers. ihe product of the type described takesparticular advantage of the enceptionally high tensile strength of theglass fibers and is, therefore, of high strength in most directionsparallel with its major faces. It is porous and sufliciently deformableto be shaped over mold surfaces when used as a reinforcement inplastics. After the stretching, the product of this invention consistsof multi-strata of glass fibers with the fibers in each stratumconsisting predominantly of bundles, all of which extend generally inthe same direction but at an angle with respect to the bundles of fibersin the adjacent strata. This product may be faced with a fabric of glassfibers in which the fibers extend angularly with respect to the fibersin the stretched fabric to provide for such angularity as will impartmore uniform and increased strength in all directions without noticeableimporosity or formability of the fabric. 7 I

Referring now to Figure 1 of the drawings, I indicates a glass meltingfurnace adapted to reciprocate back and forth the length of a rotatablewinding drum H over which it is mounted. The furnace Ill is supported oneach side by wheels I? which ride upon tracks l3 and the reciprocalmovement of the movable furnace is effected by chains l4 driven incooperation with the winding drum H or by separate power means.

The underside of the furnace I0 is provided with a bushing (not shown)having multiple openings through which streams of the molten glassfiows. These streams are attenuated into fine continuous filaments it bythe winding drum H on which they are Wound. Before being wound on thedrum, the filaments l6 are gathered into a single strand H by acollector is movable coincident with the furnace It as by being mountedon a part of the furnace structure. At the collector IS, a sizing may beapplied to the glass filaments. The sizing may be a lubricant forreducing the abrasion between the filaments, or it may be a binder whichtemporarily or permanently holds the filaments together in strands. Forsuch purposes, the size may consist of an aqueous emulsion of sulfonatedoils, starch, gelatin, polyvinyl alcohol, synthetic resins, and sugarsseparately or in various combinations.

The winding drum l l is mounted on a shaft I9 rotatably mounted inbearings 20. The shaft and drum are rotated by suitable means, such, forexample, as by gearing in engagement with the sprocket wheel 2| and, asthe drum rotates and as the furnace it and collector 18 travellongitudinally back and forth over the length of the drum, the strand isspirally wound on the drum with the lead extending in one axialdirection while the furnace is traveling in that direction and then withthe lead extending in the other axial direction as the furnace reversesits direction of travel. The traversing movement between the furnace andthe drum may be at a rate to deposit the strands in spaced apartconvolutions, as shown, or in convolutions that are in lateralcontacting relation. Thus, a layer 22 of helical strand convolutions isdeposited on the periphery of the drum and then another layer 23 ofhelical strand convolutions is deposited over the first, the strands inthe one layer crossing the strands in the other layer at an angle whichis predetermined by the relative movements between the furnace and thedrum.

It is manifest that multiple layers may be built up on the drum with thestrands in alternate layers being disposed generally in parallelrelation, though not necessarily in superposed relation, for thesubsequent layers of strands may be deposited or else shift into thecrevices 24 between the strands of the alternate layers. It is alsoapparent that this same effect may be attained if the glass meltingfurnace It and the collector [8 are held stationary while the rotatingdrum is shifted axially back and forth the length of the drum.

Instead of forming a single strand ll of the group of glass filaments[6, they preferably may be gathered to form multiple strands, such, forexample, as the three strands Ila, I12), and llc, illustrated in Figure1A of the drawings. The group of filaments may be drawn from a singleglass melting furnace or else a conjugate system of glass meltingfurnaces may be properly arranged. In either instance, the relativeaxial movement between the glass fiber forming devices and the drum Hamay be effected either by laterally traveling furnaces or else by axialreciprocation of the winding drum Ila.

The above illustrates the method of forming strands ll in which all ofthe fibers lie parallelly in the bundle. However, the strand may readilyconsist of yarns of glass fibers in which one or more strands aretwisted together but in which the fibers still extend generally in thesame direction. In its manufacture, a yarn of the type describedgenerally is divorced from the fiber forming device and as such, may bedrawn from spools and wound about the drum. In this instance, atraversing mechanism ordinarily used in the guidance of a strand duringwinding may be used for traversing the strand the length of the drumwhile it is being wound, or else the spool or drum may be movedrelatively as described in connection with the prior methods. One ormore spools of thread or strands may be used in the winding at the sametime with improved results and simplification in the process.

By either method, there is formed helical layers of glass strands l'fcomposed of multiple glass fibers or filaments extending generally inthe same direction with the strands in each layer crossing the strandsin adjacent layers at a predetermined angle. When the predeterminednumber of layers has been built up on the drum, the strand may be cutand redirected to another unit and the layers out along a line axiallyof the drum. This enables the layers to be removed from the drum as abody, which, when opened, is in the form of a fabric 25 having a lengthequivalent to the circumference of the drum and a width equal to thewidth of the drum. The fabric thus consists of multiple layers a, b, andc, of strands II with the strands in one layer b extending generally inthe same direction and angularly with respect to the strands in theadjacent layers a and 0.

Depending on the amount and type of binder in the size, a fabric may beformed in which not only are the fibers firmly held in discrete bundles,but the bundles or strands themselves are so bonded to overlying bundlesor strands at their crossings that relative movement of the fibers o1strands is rendered difficult, whereby the fabric has the property ofsufficient mass integrity to resist the stresses incident to normalhandling. This bond strength may as well be obtained by the impregnationof the fabric with a suitable binder, after the fabric i formed. Andagain, the binder in the size may be of such intermediate strength andconcentration as to retain the fibers in the strand as discrete bundleswhile enabling the bundles to move relative to each other in response toforces tensioning the mat in directions angularly with respect to thefiber lengths.

In the absence of any binder or a strong binder, the fabric 25 may beteased, a by drawing in any direction parallel with the major faces ofthe fabric other than in alignment with the strand lengths, butpreferably in a direction transverse of the width of the fabric. Duringthe drawing, the bundles of fibers are shifted angularly relative to thebundles in the adjacent layers as in the manner of a lazy tongs andlaterally relative to each other in the same layer whereby they becomefurther separated and enable the increase of the fabric dimensions andporosity while reducing its thickness andfiber concentrations. Astretched fabric of the type described is illustrated in Figure 5.

For this purpose, as illustrated in Figure 4, the fabric 25 may berolled transversely into a cylinder or package 23 and then continuouslyfed from the cylinder -between cooperating cylindrical rollers 29 whichgrip the fabric through its width. The fabric is carried off by anendless conveyor belt 33 having cooperating rollers 3i which receive theon--coming fabric. The peripheral speed of the cooperating rollers 31 isgreater than that of the cooperating feed rollers 29 and as the fabricpasses between them, it is stretched and thinned. A cutter 32 mountedforwardly of the endless conveyor belt it operates to subdivide thestretched fabric, a portion of which is illustrated in Figure 5 of thedrawings.

As the fabric is stretched transversely of its length, the strands whichoriginally extended generally lengthwise of the fabric at an acute angleof less than 45 of each other are adjusted to lie at a substantiallygreater angle to each other, such, for example, at an angle of about 60.The rollers 35 may be adapted to draw another group of parallellyarranged strands 33 from a separate roll 34 having a Width substantiallyequal to the fabric 25. These strands, which selectively may be formedof intertwisted or untwisted glass or other fibers, may be deposited onone or both faces of the fabric after the stretching operation, asparallelly arranged strands, and in this position, they more or lessintersect the angle between the strands in the fabric so that the finalproduct is a fabric with the fibers in bundles Hd which extend inseveral directions preferably at angles of about 60 one from another toprovide uniform reinforcing strengths in all directions. A fabric of thetype described is illustrated in Figure 6 of the drawings.

This figure illustrates a fabric of glass fibers formed of continuoustype fibers, that is, fibers of great and substantially continuouslengths. The fabric may equally be made of discontinuous or staple typefibers. A method of making a fabric of the latter type of fibers isillustrated schematically in Figure 3 of the drawings. In the process,streams 35 of molten glass flow from a spout 35 of a glass meltingfurnace (not fully shown) and the streams are attenuated by means of agaseous blast of air or steam 3'! to form fibers. These fibers arecollected on a drum 38 on which they are held by means of a suctionthroughout the area of a suction box 39 adjacent the inner surface ofthe drum. As the drum rotates, and carries the fibers in the directionaway from the area of the suction box, the fibers are drafted into asliver 4i! and then passed between turbinizers M to form strands 42. Inthe drafting the substantially continuous fibers are broken up intosmaller discontinuous lengths. The strand may be further processed asdescribed in direct cooperation with the fiber forming process, or elseone or more strands may be twisted together to form yarns.

The strand or yarn may then be fed onto a rotating drum 43 which issupported by a rigid frame dd mounted on wheels 55. The wheels aremovable on tracks at to enable the reciprocation of the drum axially adistance equal to its length. Thus as the drum rotates and as it travelsaxially, a helical layer of strand convolutions is formed on theperiphery of the drum, and as it travels in the opposite directionanother helical layer of strand convolutions is formed, the strands ofthe latter layer crossing the strands of the first layer at an angledetermined by the speed of rotation and axial movement of the drum.

Thus there is produced multiple layers of glass strands, which when outalong a line axially of the drum and removed therefrom, opens up into afabric with the strands in each alternate layer extending generally inthe same direction and at a predetermined acute angle relative to thestrands in the adjacent layers. Ordinarily, binders are not applied inthe discontinuous process. Thus, the stretching and thinning operationare more readily .eifected. In view of the discontinuity of the fibersin the threads, it is possible even to stretch the fabric in directionsaligned with the fiber lengths, and the greater number of free ends ofthe relatively shiftable fibers which compose the strands permitsinterfelting to the extent that greater mass integrity is obtained.

When the mat is formed of untwisted strands, and, especialy in theabsence of a strong binder, some of the fibers Hid may separate from thebundle lid under the tension of the stretching operation. Theseseparated filaments or fibers are then shiftable laterally relative ofeach other in the same layer and angularly with respect to the fibers inadjacent layers. In such instances, the fiber concentrations are furtherreduced, while the mass integrity as a result of the intertangling ofthe fibers is increased.

In either process, it is desirable to apply binders to the fabric forpurposes of holding the fibers together until subsequently processed tothe end product whether that step be carried out in the immediatevicinity or at some other remote sta ion.

It is manifest that a fabric of the type described may be manufacturedat great speed with very little low cost equipment. The fabric, initself, has the characteristics of predetermined uniform fiberdistribution at the desired angular relationship to provide for greatreinforcing strengths. The porosity and formability of the fabric allowresinous materials readily to penetrate through the fabric and enablethe fabric to be draped or wrapped over relatively sharp contours ordeeply drawn in molding operations. As a result, the fabric isparticularly well suited for the reinforcement of resinous materials inmolded or laminated plastics; as a strengthening and inert filler inshingles and pipe wraps; as a separator plate in batteries; as areinforcing fabric between fabrics of other lower strength materialssuch as paper, wood, cotton and the like, or as a fabric in itself forpurposes of insulation, construction, textiles and the like.

It is to be understood that numerous changes in details of construction,arrangement and operation of the parts comprising the apparatus'andarrangement of the glass fibers can be effected without departing fromthe spirit of the invention especially as defined in the appendedclaims.

I claim:

1. The method of producing an open mesh fabric of glass fibers whichcomprises forming and gathering multiple glass fibers into an endlessstrand, helically winding multiple layers of the strand about a housingwith the strands in one layer being angularly disposed with respect tothe strands in the adjacent layers, removing the layers from the housingin a body, said layers being out along a line crosswise of the housingin order to effect such removal, stretching the body in one or moreplanar directions simultaneously to enlarge the body while decreasingits wall thickness as a result of the relative adjustment betweenstrands in each layer and the angular adjustment of strands in adjacentlayers as well as the relative movement of the fibers in the strands,and then facing said body while the body is in a uniplanar position withone or more layers of a glass fabric having the fibers therein extendingin parallel relation and generally in a direction which is angular withrespect to the fibers in the body.

2. The method of producing an open mesh fabric of glass fibers asclaimed in claim 1, in which the body of strands of fibers removed fromthe drum is rolled in the direction of its side walls into a package,and the body is stretched 8 in that direction in connection with itsbeing unrolled from the package.

GAMES SLAY'I'ER.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,771,216 Gossler July 22, 1930 2,081,060 Modigliani May 18,1937 2,234,986 Slayter et a1. Mar. 18, 1941 2,392,805 Biefeld Jan, 15,1946 2,477,555 Roberts et a1. July 26, 1949 2,574,221 Modigliani Nov. 6,1951

1. THE METHOD OF PRODUCING AN OPEN MESH FABRIC OF GLASS FIBERS WHICHCOMPRISES FORMING AND GATHERING MULTIPLE GLASS FIBERS INTO AN ENDLESSSTRAND, HELICALLY WINDING MULTIPLE LAYERS OF THE STRAND ABOUT A HOUSINGWITH THE STRANDS IN ONE LAYER BEING ANGULARLY DISPOSED WITH RESPECT TOTHE STRANDS IN THE ADJACENT LAYERS, REMOVING THE LAYERS FROM THE HOUSINGIN A BODY, SAID LAYERS BEING CUT ALONG A LINE CROSSWISE OF THE HOUSINGIN ORDER TO EFFECT SUCH REMOVAL, STRETCHING THE BODY IN ONE OR MOREPLANAR DIRECTIONS SIMULTANEOUSLY TO ENLARGE THE BODY WHILE DECREASINGITS WALL THICKNESS AS A RESULT OF THE RELATIVE ADJUSTMENT BETWEENSTRANDS IN EACH LAYER AND THE ANGULAR ADJUSTMENT OF STRANDS IN ADJACENTLAYERS AS WELL AS THE RELATIVE MOVEMENT OF THE FIBERS IN THE STRANDS,AND THEN FACING SAID BODY WHILE THE BODY IS IN A UNIPLANAR POSITION WITHONE OR MORE LAYERS OF A GLASS FABRIC HAVING THE FIBERS THEREIN EXTENDINGIN PARALLEL RELATION AND GENERALLY IN A DIRECTION WHICH IS ANGULAR WITHRESPECT TO THE FIBERS IN THE BODY.